Noob M50 swap questions

[MaksV]

I am about to start on my first swap. Picked up an NV m50 tonight with all the accessories that supposed to be in good condition. I bolded and numbered my questions to make it easier to answer them. Please dont tell me to search, I have spent the last two days reading, and these details are either not talked about or slipped through my search.

TIA for your help guys...

General plan:
1. rebuild the m50
-new seals
-prep for boost
-headers
2. pull m20
-pull front clip?
-remove engine
-rebuild transmission - new seals
-move brake boster
3. assemble
-put tranny on fresh m50
4.stick it back in the car
-connect driveshaft
-connect AC
-connect fuel
-connect electricity
5. reassemble car and drive away

shopping list -tentative -


1. I have an engine out of a 525i - can I use teh alloy engine arms? or do I need to get the e36 ones?

2. The engine is a junkyard pull, so they cut the harness. I have a bunch of wires coming out. is this a pain or opportunity? can I get a plug with pigtails? or should I just get a new harness for the engine?

3. He gave me a 402 DME - is there any difference betweent the 402 and the 403?

4. I plan on going FI later. What does my FI specific checklist consist of?
-drill/tap/weld points for future oil hookup
-seal the CCV tube
-i am gonna run a stock HG and bolts for now...

5. I am a little confused about AC hookup. Can I simply use my m20 compressor? it is good, and I dont know about the m50 one. If I buy those convertors mentioned in the other thread can i just screw the fitting together?

6. is the steering rack swap worth it? It is adding a 300 bucks to a tight budget and I was wondering if it was worth it. I have new endlinks on my current rack and I dont have an issue with it even at autocrosses...

7. if you install ebay headers how do you connect them to stock exhaust? anyone have any pics? I am not scared of cutting and welding but just would love to see some shots....

8. I have the m50 shorty headers on my block. Can I connect them in the same place as the stock m20 shorty headers connect? I will build a 3" system later as funds permit, but is this possible?

9. Please take a look at my buy list and see if I am mission anything. I am going to take a closer look at the engine before finalizing this list as I am sure more stuff will come up.

10. I am keeping my trans, so I am not sure about the flywheel machining part. What is the lightest M20 flywheel? what is the most cost effective (to weight ratio)? what part is supposed to be machined down exactly? anyone have pics?

11. To do the swap itself - is it easier to remove hood and drop car front low and try to wiggle the assembly in ? or is it just easier to take the front clip off, and be able to go in and out easily?

12. any tips/tricks/things I am missing?

[glucklich21]

Since you're local, I'll be nice. ;)

I am about to start on my first swap. Picked up an NV m50 tonight with all the accessories that supposed to be in good condition. I bolded and numbered my questions to make it easier to answer them. Please dont tell me to search, I have spent the last two days reading, and these details are either not talked about or slipped through my search.

TIA for your help guys...

General plan:
1. rebuild the m50
-new seals
-prep for boost -do not both with this unless you're fully committed to that
-headers
2. pull m20
-pull front clip? -not possible on the E30
-remove engine
-rebuild transmission - new seals
-move brake booster -LKQ Northville reguarly have 735i's, it's $45 for a booster, get one.
3. assemble
-put tranny on fresh m50
4.stick it back in the car
-connect driveshaft
-connect AC
-connect fuel
-connect electricity
5. reassemble car and drive away

shopping list -tentative -

1. I have an engine out of a 525i - can I use teh alloy engine arms? or do I need to get the e36 ones?

E36 arms, I have some you can have for free, since I got them for free.

2. The engine is a junkyard pull, so they cut the harness. I have a bunch of wires coming out. is this a pain or opportunity? can I get a plug with pigtails? or should I just get a new harness for the engine?

Get a new harness

3. He gave me a 402 DME - is there any difference betweent the 402 and the 403? If your M50 is a Non vanos like you say, neither of those will work, you need a green label 405. Those two are for vanos models. Sell it

4. I plan on going FI later. What does my FI specific checklist consist of?
-drill/tap/weld points for future oil hookup
-seal the CCV tube
-i am gonna run a stock HG and bolts for now...

Like I said earlier, don't bother with this unless you are fully committed. Even if you are, you have a lot of research to do.


5. I am a little confused about AC hookup. Can I simply use my m20 compressor? it is good, and I dont know about the m50 one. If I buy those convertors mentioned in the other thread can i just screw the fitting together?

You use the M50 compressor, just splice the M50 lines into the stock e30 lines.

6. is the steering rack swap worth it? It is adding a 300 bucks to a tight budget and I was wondering if it was worth it. I have new endlinks on my current rack and I dont have an issue with it even at autocrosses...

7. if you install ebay headers how do you connect them to stock exhaust? anyone have any pics? I am not scared of cutting and welding but just would love to see some shots....

You can't use the stock system. Even if you manage to hook it up, it's too restrictive.

8. I have the m50 shorty headers on my block. Can I connect them in the same place as the stock m20 shorty headers connect? I will build a 3" system later as funds permit, but is this possible?

9. Please take a look at my buy list and see if I am mission anything. I am going to take a closer look at the engine before finalizing this list as I am sure more stuff will come up.

I'll take a look at this later

10. I am keeping my trans, so I am not sure about the flywheel machining part. What is the lightest M20 flywheel? what is the most cost effective (to weight ratio)? what part is supposed to be machined down exactly? anyone have pics?

The 323i flywheel is the lightest stock, bolts directly up, and it's one of the better choices than machining the flywheel, but I ended up buying a new one because of its scarcity. However since you're on a strict budget machining will be your best option.

11. To do the swap itself - is it easier to remove hood and drop car front low and try to wiggle the assembly in ? or is it just easier to take the front clip off, and be able to go in and out easily?

Can't remove the front clip, it's welded in place. The only part you can remove is the valence and fenders, the radiator support stands in your way after that.

12. any tips/tricks/things I am missing?

You need to do some more research. ;)

[EduardoGomez]

Go read my swap project post, it will answer many of your questions. To put the engine in you need a "tilter" because front radiator/hood support is welded on E30 chassis and it is not removable.

http://www.r3vlimited.com/board/showthread.php?t=207657

[rotarievtec]

If you need a 405 dme I got one pm me if interested.
Also i took my stock i single mass flywheel and had the back shaved down. When you try to mount it you will see where it needs shaved. My machine shop charged me like 40 bucks to surface the flywheel and shave the back.

[MaksV]

Pms about arms, and DME sent. I will do some more reading. If anyone has a NV M50 harness or MAF let me know.

I will have more questions later.

[Jand3rson]

If you need a 405 dme I got one pm me if interested.
Also i took my stock i single mass flywheel and had the back shaved down. When you try to mount it you will see where it needs shaved. My machine shop charged me like 40 bucks to surface the flywheel and shave the back.

Damn, that's good, the Napa machine shop charged me $87 for a resurface and for shaving the back down, I had them take it down to about 1mm above the ring gear.